Research expedition M148-2 took place from July 2nd, 2018 (Walvis Bay, Namibia) to July 20th, 2018 (Las Palmas, Spain). CTD data for 7 stations with a total of 14 individual casts along the cruise track were recorded using a Sea & Sun Technology CTD90M (SN 979) down to depths of 500m. The CTD was equipped with the following sensors: Temperature sensor Pt100 model 1509 (Thermal Developments International), Conductivity sensor 7-pole platinum coated electrode cell in quartz glass (Sea & Sun Technology), Seapoint Chlorophyll Fluorometer (Seapoint) and dissolved oxygen sensor (DO522M18, Clark type, OxyGuard). The data files contain the data for temperature, salinity, density, chlorophyll a concentration and oxygen concentration; as raw data and processed and flagged according to the recommendations for real-time data processing of EuroGOOS and GTSPP, as well as the outlier detection method CoTeDe (https://github.com/castelao/CoTeDe). Biogeographic regions are determined according to Spalding et al. (2012). TEOS-10 unit conversions have been performed with the GSW Oceanographic Toolbox (McDougall and Barker, 2011).